There is a system that runs a plurality of virtual machines (VM) on a server and allocates these virtual machines to terminals, which are connected to the server via a network. In this system, an operating system (OS) runs on each VM running on the server, and the user of each terminal uses the OS running on the VM allocated to the terminal. In other words, the server is used as a desktop computer of each terminal.
Japanese Laid-open Patent Publication No. 2006-072591 discusses a method of controlling a virtual machine when a failure occurs in the virtual machine by pausing the running virtual machine experiencing the failure, transferring the state of the paused virtual machine to another computer, and reconstructing the transferred state of the virtual machine in the other computer.